Merge tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "This update has successfully completed a 0day-kbuild run and has
  appeared in a linux-next release.  The changes outside of the typical
  drivers/nvdimm/ and drivers/acpi/nfit.[ch] paths are related to the
  removal of IORESOURCE_CACHEABLE, the introduction of memremap(), and
  the introduction of ZONE_DEVICE + devm_memremap_pages().

  Summary:

   - Introduce ZONE_DEVICE and devm_memremap_pages() as a generic
     mechanism for adding device-driver-discovered memory regions to the
     kernel's direct map.

     This facility is used by the pmem driver to enable pfn_to_page()
     operations on the page frames returned by DAX ('direct_access' in
     'struct block_device_operations').

     For now, the 'memmap' allocation for these "device" pages comes
     from "System RAM".  Support for allocating the memmap from device
     memory will arrive in a later kernel.

   - Introduce memremap() to replace usages of ioremap_cache() and
     ioremap_wt().  memremap() drops the __iomem annotation for these
     mappings to memory that do not have i/o side effects.  The
     replacement of ioremap_cache() with memremap() is limited to the
     pmem driver to ease merging the api change in v4.3.

     Completion of the conversion is targeted for v4.4.

   - Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem
     driver, update the VFS DAX implementation and PMEM api to provide
     persistence guarantees for kernel operations on a DAX mapping.

   - Convert the ACPI NFIT 'BLK' driver to map the block apertures as
     cacheable to improve performance.

   - Miscellaneous updates and fixes to libnvdimm including support for
     issuing "address range scrub" commands, clarifying the optimal
     'sector size' of pmem devices, a clarification of the usage of the
     ACPI '_STA' (status) property for DIMM devices, and other minor
     fixes"

* tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (34 commits)
  libnvdimm, pmem: direct map legacy pmem by default
  libnvdimm, pmem: 'struct page' for pmem
  libnvdimm, pfn: 'struct page' provider infrastructure
  x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB
  add devm_memremap_pages
  mm: ZONE_DEVICE for "device memory"
  mm: move __phys_to_pfn and __pfn_to_phys to asm/generic/memory_model.h
  dax: drop size parameter to ->direct_access()
  nd_blk: change aperture mapping from WC to WB
  nvdimm: change to use generic kvfree()
  pmem, dax: have direct_access use __pmem annotation
  dax: update I/O path to do proper PMEM flushing
  pmem: add copy_from_iter_pmem() and clear_pmem()
  pmem, x86: clean up conditional pmem includes
  pmem: remove layer when calling arch_has_wmb_pmem()
  pmem, x86: move x86 PMEM API to new pmem.h header
  libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option
  pmem: switch to devm_ allocations
  devres: add devm_memremap
  libnvdimm, btt: write and validate parent_uuid
  ...

1 files changed, 84 insertions, 31 deletions

diff --git a/include/linux/pmem.h b/include/linux/pmem.h
index d2114045a6c4..85f810b33917 100644
--- a/include/linux/pmem.h
+++ b/include/linux/pmem.h
@@ -14,28 +14,42 @@
 #define __PMEM_H__
 
 #include <linux/io.h>
+#include <linux/uio.h>
 
 #ifdef CONFIG_ARCH_HAS_PMEM_API
-#include <asm/cacheflush.h>
+#define ARCH_MEMREMAP_PMEM MEMREMAP_WB
+#include <asm/pmem.h>
 #else
+#define ARCH_MEMREMAP_PMEM MEMREMAP_WT
+/*
+ * These are simply here to enable compilation, all call sites gate
+ * calling these symbols with arch_has_pmem_api() and redirect to the
+ * implementation in asm/pmem.h.
+ */
+static inline bool __arch_has_wmb_pmem(void)
+{
+	return false;
+}
+
 static inline void arch_wmb_pmem(void)
 {
 	BUG();
 }
 
-static inline bool __arch_has_wmb_pmem(void)
+static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,
+		size_t n)
 {
-	return false;
+	BUG();
 }
 
-static inline void __pmem *arch_memremap_pmem(resource_size_t offset,
-		unsigned long size)
+static inline size_t arch_copy_from_iter_pmem(void __pmem *addr, size_t bytes,
+		struct iov_iter *i)
 {
-	return NULL;
+	BUG();
+	return 0;
 }
 
-static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,
-		size_t n)
+static inline void arch_clear_pmem(void __pmem *addr, size_t size)
 {
 	BUG();
 }
@@ -43,18 +57,22 @@ static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,
 
 /*
  * Architectures that define ARCH_HAS_PMEM_API must provide
- * implementations for arch_memremap_pmem(), arch_memcpy_to_pmem(),
- * arch_wmb_pmem(), and __arch_has_wmb_pmem().
+ * implementations for arch_memcpy_to_pmem(), arch_wmb_pmem(),
+ * arch_copy_from_iter_pmem(), arch_clear_pmem() and arch_has_wmb_pmem().
  */
-
 static inline void memcpy_from_pmem(void *dst, void __pmem const *src, size_t size)
 {
 	memcpy(dst, (void __force const *) src, size);
 }
 
-static inline void memunmap_pmem(void __pmem *addr)
+static inline void memunmap_pmem(struct device *dev, void __pmem *addr)
+{
+	devm_memunmap(dev, (void __force *) addr);
+}
+
+static inline bool arch_has_pmem_api(void)
 {
-	iounmap((void __force __iomem *) addr);
+	return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API);
 }
 
 /**
@@ -68,14 +86,7 @@ static inline void memunmap_pmem(void __pmem *addr)
  */
 static inline bool arch_has_wmb_pmem(void)
 {
-	if (IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API))
-		return __arch_has_wmb_pmem();
-	return false;
-}
-
-static inline bool arch_has_pmem_api(void)
-{
-	return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API) && arch_has_wmb_pmem();
+	return arch_has_pmem_api() && __arch_has_wmb_pmem();
 }
 
 /*
@@ -85,16 +96,24 @@ static inline bool arch_has_pmem_api(void)
  * default_memremap_pmem + default_memcpy_to_pmem is sufficient for
  * making data durable relative to i/o completion.
  */
-static void default_memcpy_to_pmem(void __pmem *dst, const void *src,
+static inline void default_memcpy_to_pmem(void __pmem *dst, const void *src,
 		size_t size)
 {
 	memcpy((void __force *) dst, src, size);
 }
 
-static void __pmem *default_memremap_pmem(resource_size_t offset,
-		unsigned long size)
+static inline size_t default_copy_from_iter_pmem(void __pmem *addr,
+		size_t bytes, struct iov_iter *i)
+{
+	return copy_from_iter_nocache((void __force *)addr, bytes, i);
+}
+
+static inline void default_clear_pmem(void __pmem *addr, size_t size)
 {
-	return (void __pmem __force *)ioremap_wt(offset, size);
+	if (size == PAGE_SIZE && ((unsigned long)addr & ~PAGE_MASK) == 0)
+		clear_page((void __force *)addr);
+	else
+		memset((void __force *)addr, 0, size);
 }
 
 /**
@@ -109,12 +128,11 @@ static void __pmem *default_memremap_pmem(resource_size_t offset,
  * wmb_pmem() arrange for the data to be written through the
  * cache to persistent media.
  */
-static inline void __pmem *memremap_pmem(resource_size_t offset,
-		unsigned long size)
+static inline void __pmem *memremap_pmem(struct device *dev,
+		resource_size_t offset, unsigned long size)
 {
-	if (arch_has_pmem_api())
-		return arch_memremap_pmem(offset, size);
-	return default_memremap_pmem(offset, size);
+	return (void __pmem *) devm_memremap(dev, offset, size,
+			ARCH_MEMREMAP_PMEM);
 }
 
 /**
@@ -146,7 +164,42 @@ static inline void memcpy_to_pmem(void __pmem *dst, const void *src, size_t n)
  */
 static inline void wmb_pmem(void)
 {
-	if (arch_has_pmem_api())
+	if (arch_has_wmb_pmem())
 		arch_wmb_pmem();
+	else
+		wmb();
+}
+
+/**
+ * copy_from_iter_pmem - copy data from an iterator to PMEM
+ * @addr:	PMEM destination address
+ * @bytes:	number of bytes to copy
+ * @i:		iterator with source data
+ *
+ * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
+ * This function requires explicit ordering with a wmb_pmem() call.
+ */
+static inline size_t copy_from_iter_pmem(void __pmem *addr, size_t bytes,
+		struct iov_iter *i)
+{
+	if (arch_has_pmem_api())
+		return arch_copy_from_iter_pmem(addr, bytes, i);
+	return default_copy_from_iter_pmem(addr, bytes, i);
+}
+
+/**
+ * clear_pmem - zero a PMEM memory range
+ * @addr:	virtual start address
+ * @size:	number of bytes to zero
+ *
+ * Write zeros into the memory range starting at 'addr' for 'size' bytes.
+ * This function requires explicit ordering with a wmb_pmem() call.
+ */
+static inline void clear_pmem(void __pmem *addr, size_t size)
+{
+	if (arch_has_pmem_api())
+		arch_clear_pmem(addr, size);
+	else
+		default_clear_pmem(addr, size);
 }
 #endif /* __PMEM_H__ */